<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>样式演示</title>
    <style>
        div{
            border: 1px solid cadetblue;
        }
        .left{
            width: 20%;
            float: left;
        }
        .center{
            width: 59%;
            float: left;
        }
        .right{
            width: 20%;
            float: left;
        }
        .footer{
            clear: both;
            background: cornflowerblue;
            text-align: center;
        }
    </style>
</head>
<body>
    <div>top</div>
    <div>navibar</div>
    <div class="left">left</div>
    <div class="center"><img src="../img/ad2.jpg" title="广告" alt="找不到该图片" width=100% height=300%/></div>
    <div class="right">right</div>
    <div class="footer">footer</div>
</body>
</html>